1. Field of the Invention
The present invention relates to a liquid crystal display device, in particular, a driving method of a liquid crystal display device. In addition, the present invention relates to a liquid crystal display device using the driving method and an electronic device including the liquid crystal display device.
2. Description of the Related Art
In recent years, display devices such as a liquid crystal display device and a light-emitting display device have been actively developed to be used for a personal computer, a mobile device, and a liquid crystal television. In particular, the display devices are required to have a high resolution. However, in the current display devices, a pixel portion is formed using three pixels for red (hereinafter abbreviated as R), green (hereinafter abbreviated as G), and blue (hereinafter abbreviated as B); thus, there is a limitation on increase in resolution of the liquid crystal display devices.
In order to solve the above problem, a driving method called a field sequential driving method has been researched. In a field sequential driving method, backlights are sequentially switched, and light of R, G, and B is supplied to a display panel; therefore, R, G, and B can be expressed in one pixel. However, in a field sequential driving method, a video signal has to be written into a pixel at a speed that is three times higher than that of a normal liquid crystal display device. Therefore, a liquid crystal element cannot respond in time, and there is a problem in that a correct gray scale cannot be expressed.
Therefore, in a field sequential driving method disclosed in Patent Document 1 (Japanese Patent No. 3338438), in order to solve the problem of the low response speed of a liquid crystal element, the transmissivity of a liquid crystal element is changed over time so that a correct gray scale is expressed.